Flame igniter for jet propulsion units



Nov. 13, 1951 F. A. PARKER, JR 2,574,495

FLAME IGNITER FOR JET PROPULSION UNITS Filed May 16, 1945 2SI'EETSf-ISHEET 1 m g FRANK A.PARKER,JR

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Nov. 13, 1951 F. A. PARKER, JR 2,574,495

FLAME IGNITER FOR JET PROPULSION UNITS Filed May 16, 1945 2 SHEETS-SHEET 2 zflllfl/ ull.

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Patented Nov. 13, 1951 UNITED FLAME IGNITER FOR JET PROPULSION UNITSFrank A. Parker, Jr., United States Navy Application May 16,1945,`Serial No. 594,129

(Cl. Gil-39.14;)

(emma under che act of March zi, isss, n amended April 30, 1928; 370 0.G. 757) 10 Claims.

v like.

When the above propellants in combination are subjected to an intenseflame they are heated sufficiently to ignite and oxidize the fuel,resulting in the desired expansion and effecting a propulsive jet fromthe discharge nozzle of the unit,

The present invention is particularly directed to an improved starterfor liquid jet propulsion units and has as one object the provision ofcompact means supplying a pilot flame to positively ignite thepropellants, which means is loperated independently of the main fuelnozzle.

An additional object of the present invention isvto provide in a jetpropulsion starter assembly, combined fluid flow control means and sparkproducing means which may be operated to furnish the initial heat ofcombustion Ifor propulsion starting purposes.

A further object is to provide an independent liquid propellant ignitingand burning device continued operation of which serves to protectportions of the starter mechanism from damage by the heat of normalcombustion.

It is a further object to combine in a pilot combustion supply devicemeans for protecting said device against the products of combustion andmeans for automatically terminating a portion of the pilot operationupon proper ignition K of the main -fuel charge.

Other objects and advantages will be hereinafter more fully describedand for a complete understanding of the nature, scope andcharacteristics of this invention reference may now be had to thefollowing description and accompanying drawings, in which latter:

Fig. 1 illustrates a schematic fuel system partially in verticalcross-section showing one embodiment of the present invention.

Fig. 2 is a schematic fuel system showing another embodiment of thepresent invention.

`The system employed may comprise a high pressure tank I0 containing asuitable gas under very high pressure the discharge of which throughline Il may be controlled by means of reducing valve I2. The gas underhigh pressure then passes to a T connection I3 where it 'is distributedthrough lines I4 and I5, as shown. Line I4 applies pressure to a mainpropellant fuel tank I6 while through line I5 pressure is applied to aliquid propellant or oxidizer tank l1. Discharge of propellant liquidfrom these tanks through lines i8 and i9 may be controlledsimultaneously by electrically operated valves 20 and 2l to permit thecontents to be directed into the usual liquid combining nozzle 22. Asuitable electrical switch 21a may be provided so as to operate thevalves 20 and 2| together.

'I'he nozzle 22 discharges into an enlarged spherical combustion chamber23, as shown, and the propellant liquids when they are ignitedforcefully expand and emerge through jet propulsion nozzle 24 to providethe desired propulsion effect.

A T connection 25 may be provided leading a portion of the contents fromthe main fuel tank I6 through line 26 where its flow is controlled bymeans of a separate electrically controlled igniter valve 21, theoperation of which may likewise be controlled by means of a suitableelectrical circuit including switch 28, as shown. Fuel from valve 21 isthen conducted through line 29 to an annular recess 30 in a startervalve seat housing 3l.

The starter mechanism of the present invention comprises the valve seathousing 3l which is provided with a plurality of seat encirclingapertures 32 leading from the annular recess 30 and through which liquidpropellant from tank I6 is projected into the combustion chamber 23. Asthe fuel so supplied must be mixed with air or another oxidizer beforeit can be ignited for starting purposes there is provided a separatemotor driven blower 33 which forces air through conduit 34 into thespace 35 within the valve seat housing and from the lower portion ofwhich it emerges to mix with the liquid fuel emerging from the inwardlydirected apertures 32 rforming therewith a suitable combustible mixture.An inlet valve 3G having a head 31 may be employed to control the airflow in a manner hereinafter to be described. l

In order to ignite the fuel and air mixture thus provided, a hightension electric spark may be caused to jump from the head 31 of thevalve to a seat 38 thereby igniting the fuel and air mixture. This hightension current may be supplied in any desired manner as well known inthe art through a suitable cable 39 which is connected to the upper endof the stem of valve 31. This stem is mounted for vertical reciprocationin a block 40 of suitable insulating material and is surroundedby acompression 4spring ll which bears against washer 42 secured on the stemand normallyfurges the valve into the open position as shown.

In operation, valve I2 is flrst opened to permit pressure to be appliedto the liquid propellant in tanks I6 and |1. No propellant can passthrough valves 28 and 2| since they are closed, however, liquid fuel maypass through line 2B to valve 21. Valve 21 may then be opened by theoperation of switch 28 to permit fuel under pressure to flow throughline 28 and emerge from the inwardly directed apertures 32 whichsurround the valve seat.

Simultaneously with the above described procedure the electrically.operated blower 33 may be started as by means of the electrical circuit28a whereby it will deliver air through conduit 3l so that it emerges'through the angular space surrounding the valve.

Concurrently with the above a high voltage current may beA suppliedthrough conductor 39 and be caused to jump across the space from thehead 31 of the valve to seat 38 effecting instantaneous ignition of thecombined fuel and air mixture. I

It will be apparent that the combustion thus occurring within thecombustion chamber slightly increases the pressure therein, however,spring 4| is of suflicient strength to prevent the valve from beingclosed by the amount of pressure so created.

With the pilot flames produced and in operation as above describedvalves 20 and 2| may thereupon be opened by operation of electricalcontrol switch 2la so that liquid fuel and oxidizing mixture in thedesired proportions may be forced from supply chambers I8 and I1 intothe discharge nozzle 22 from which they emerge into the combustionchamber 23. The liquid propellants so supplied are immediately ignitedby the intense heat already existing within the combustion chamber 23 byreason of the pilot iiame. The greatly increased temperature andresulting rise in pressure is now sufficient to overcome spring 4| andforces the valve head 31 upon the seat 38.

Because of the intense temperature rise which exists within thecombustion chamber 23 liquid fuel is supplied to the valve seat duringthe entire jet operation and emerges from the apertures 32 beingdirected by these apertures in a spray over the valve head 31. Theeilect of this operation is to blanket or protect the valve head 31 fromthe heat, cooling the head and preventing warping or other deleteriouseffects as a result of this heat. ,l

When valves 28 and 2| are closed the propellant chamber pressure dropsand permits the spring loaded valve to lift from its seat. The ignitermay then be operated as before and continues to operate as desired.

In the'embodiment illustrated in Fig. 2 a modication of the presentinvention is shown Wherein the igniter heretofore described may beadapted for use with a monopropellant such for example as nitromethane(CHaNOz). In this embodiment the nitromethane takes the place of boththe fuel and the oxidizer and may be stored in a single fuel tank orthere may be provideda monopropellant tank 50 and an ignitor fuel tankwhich later may contain 4 either the monopropellant or a separateigniter fluid.

When separate tanks are employed the monopropellant may be led from tank50 through line 52 controlled by valve 53 which may be remotely operatedby means of switch 54. Monopropellant is thus conducted to the main fuelnozzle 22 in the manner hereinbefore described with regard to the firstembodiment.

In Fig. 2 the igniter fuel tank 5| is shown connected by outlet line 55to the igniter nozzle and the flow may be controlled by the valve 21 aswas hereinbefore described with respect to the first embodiment.

vIn operation the device of the second embodiment, whether employingmonopropellant or some other fluid for ignition purposes, conducts fuelfrom tank 5| to the ignition chamber where it is mixed with air enteringthrough conduit 3l and by the means hereinbefore described is ignited tcprovide a pilot iiame in the combustion chamber. Monopropellantsubsequently injected from the main discharge nozzle may be ignited bythis pilot flame. If monopropellant alone is to be used for both theignition and mam discharge jets then obviously tanks 50 and 5| may becombined.

From the foregoing description it will be apparent to those skilled inthe art that various modications thereof may be made without departingfrom the spirit and scope of this invention and it is desired,therefore, that the same be limited only by the scope of the appendedclaims.

The invention described herein may be manufacturedand used by or for theGovernment of the United States of America for governmental purposeswithout the payment of any royalties thereon or therefor.

Having thus described the invention, what is claimed and desired to besecured by Letters Patent is:

1. In an apparatus for producing jet reaction motive force wherein anon-spontaneously ignitable main combustible charge is injected andburned, means for initiating ignition 0f said main charge comprising acombustion chamber, means for delivering a liquid fuel supply into thecombustion chamber, means for delivering an oxygen supply into thecombustion chamber to form an ignitable mixture with the liquid fuelsupply, means in said combustion chamber for controlling the oxygensupply comprising a movable valve at the outlet from said oxygendelivery means normally biased inwardly in the open position, and meansfor igniting the mixture to provide an initial combustion flame forsubsequent ignition of the main charge.

2. In an apparatus for producing jet reaction motive force having acombustion chamber wherein a non-spontaneously ignitable main.combustible charge is injected and burned, means for initiating ignitionof said main charge comprising means for delivering a liquid fuel supplyinto said combustion chamber, means for delivering an oxygen supply intosaid combustion chamber to form an ignitable mixture with the liquidfuel supply, means in said combustion chamber for controlling the oxygensupply comprising a movable valve at the outlet from said oxygendelivery means normally biased inwardly in the open position from itsseat and electrical means for igniting the mixture including the movableoxygen valve whereby an electric spark is caused to jump from the valveto the adjacent valve seat.

3. In an apparatus for producing jet reaction s motive force having acombustion chamber wherein a non-spontaneously ignitable maincombustible charge is injected and burned, means for initiating ignitionof the said main combustible charge comprising, means for delivering aliquid fuel supply inw said combustion chamber, means for delivering anoxygen supply into said combustion chamber for form an ignitable mixturewith the liquid fuel'supply, pressure responsive means in said chamberfor interrupting the oxygen supply upon combustion of the main charge,and electrical means for igniting the initial oxygen and fuel supplymixture, the pressure responsive means also serving to interrupt theelectrical means upon interruption of the oxygen supply.

comprising, a valve seat assembly in communication with said combustionchamber, means for delivering a liquid fuel supply to the valve seatthrough a plurality of perforations forming supply ports to saidcombustion chamber, means for delivering an oxygen supply to the valveseat assembly and said combustion chamber adjacent the liquid fuelsupply ports, control means for interrupting the oxygen supply, thecontrol means being responsive to the pressure of combustion of the maincharge within the combustion chamber, and resilient means normallyrendering the control means ineffective until combustion of the maincombustible charge in the chamber.

5. In an apparatus for producing jet reaction motive force having acombustion chamber wherein a non-spontaneously ignitable liquid maincombustible charge is injected and burned, means for initiating ignitionof said main charge comprising. a valve seat assembly in communicationwith said combustion chamber having a plurality of perforations formingsupply ports for delivering liquid fuel to said combustion chamber,means for leading aliquid fuel supply to the valve seat assembly, meansfor leading an oxygen supply to the valve seat assembly and fordelivering it into said combustion chamber adjacent the liquid fuelsupply ports, control means for interrupting the oxygen supply, thecontrol means being responsive to the pressure within said combustionchamber, and resilient means normally rendering the control meansineffective until combustion of the main combustible charge in thechamber.

6. In an apparatus for producing jet reaction motive force having acombustion chamber wherein a non-spontaneously ignitable liquid maincombustible charge is injected and burned, means for initiating ignitionof said main charge comprising, a valve seat assembly in communicationwith said combustion chamber, and having a central passage and a,plurality of perforations forming supply ports for delivering liquidfuel to said combustion chamber, means for leading a liquid fuel supplyto said valve seat assembly, means for leading an oxygen supply tothevalve seat assembly and for delivering it into the said combustionchamber adjacent the liquid fuel supply ports, control means forinterrupting the oxygen supply, the controlmeans being responsive to thepressure within said combustion chamber, resilient means normallyrendering the control means ineective until combustion of the maincombustible charge in the chamber, and

electric ignition means for igniting the fuel and oxygen mixture.

y '1. In an apparatus for producing jet reaction motive force wherein anon-spontaneously ignitable liquid main combustible charge is injectedand burned, a combustion chamber, means for delivering liquid fuel underpressure into the combustion chamber, means for delivering an oxidizerunder pressure in the combustion chamber, a main mixing nozzle forcombining the fuel and oxidizer into an ignitable mixture, a separatecombustion initiating starter nozzle, means for supplying liquid fuelunder pressure to the starter nozzle, means for forcing air through thestarter nozzle, an igniter base having ports for delivering the liquidfuel and air simultaneously into the combustion chamber, an air controlvalve for automatically interrupting the air supply after ignition ofthe main charge, and resilient means preventing interruption of the airsupply until ignition of the main charge.

8. In an apparatus for producing jet reaction motive force whereinnon-spontaneously ignitable liquid main combustible charge is injectedand burned, a combustion chamber, means for delivering liquid fuel underpressure into the combustion chamber, means for delivering an oxidizerunder pressure into the combustion chamber, a main mixing nozzle forcombining the fuel and oxidizer into an ignitable mixture, a separatecombustion initiating starter nozzle, means for delivering a liquid fuelsupply under pressure to the starter nozzle, means for supplying airunder pressure to said nozzle, an igniter base having ports fordelivering the liquid fuel and air simultaneously into the combustionchamber, a

control valve for automatically interrupting the.

air supply after ignition of the main charge, resilient means preventinginterruption of the air supply until ignition of the main charge, andignition means including a movable portion of said valve for ignitingthe combustion initiating charge.

9. In an apparatus for producing jet reaction motive force whereinnon-spontaneously ignitable liquid main combustible charge is injectedand burned. means for initiating ignition of the main charge comprising,a combustion chamber having a mixing nozzle and said main charge, meansfor delivering a liquid fuel supply into the combustion chamber throughsaid mixing nozzle,

means for delivering an oxygen supply into the combustion chamberthrough the mixing nozzle, remote control means for controlling saidfuel supply means and the oxygen supply means, an igniter nozzle, meansfor delivering an igniter liquid fuel supply into the igniter nozzle, aseparate means for delivering an oxidizer supply into the igniternozzle, remote control means for simultaneously initiating the igniterliquid fuel supply means and igniter oxidizer supply means, meansresponsive to the pressure in the combustion chamber for interruptingthe oxidizer supply independently of the liquid fuel supply, and meansfor igniting the igniter liquid fuel and oxidizer supply within thecombustion chamber.

10. In an apparatus for producing jet reaction motive forces wherein anonspontaneously ignitable liquid propellant is burned, a combustionchamber, a main fuel nozzle and an igniter fuel nozzle for said chamber,means for delivering the liquid propellant to said main fuel nozzle andmeans for delivering the liquid propellant to said igniter fuel nozzle,said last named means including igniter means arranged to automatically'dlsoontlnue' operation in response to pressure of combustion of thepropellant discharged by the main fuel nozzle.

FRANK A. PARKER. Jn.

REFERENCES CITED 8 v UNITED STATES PATENTS y Number Name l Date HubbellMay 31, 1927 Rogers ..-.1 June 17,1930 Goddard Sept. 27, 1932 ChandlerNov.- 8, 1932 Aldrich Dec. 6, 1932 Goddard Aug. 17, 1937 Zieler Feb. 24,1942

